Purity >95%. Z-VAD(OMe)-FMK is a cell-permeable, competitive, and irreversible inhibitor of all caspases. Through this action, it inhibits cleavage of poly(ADP-ribose) polymerase, preventing apoptosis when used at 10-50 μM. It also blocks caspase-mediated apoptosis in vivo . Z-VAD(OMe)-FMK effectively prevents caspase action in inflammasomes.